This invention relates to a laminating device, and particularly concerns a laminating device which is able to warm up to its operating temperature within a relatively short space of time.
Laminating devices are widely used for sealing items within translucent or transparent pouches, so that the items can be displayed and/or stored and remain protected from dirt, moisture and so on.
One problem with most conventional laminating machines is that, when the machine is initially switched on, it takes a relatively long time before the machine is ready to perform a laminating operation. This is because the rollers of the machine must be heated up to a high temperature. In conventional laminating machines, each roller is partially surrounded by a heavy “shoe” formed from a material such as aluminum. The shoes are heated, typically by resistance heating, and heat energy is transferred from the shoes to the rollers by radiation and convection.
While shoes of this type have proved to be effective at maintaining the rollers at the desired operating temperature, it will be appreciated that laminating machines using this technique will take a considerable length of time for the rollers to reach a suitable laminating temperature.
More recently, it has been proposed to heat the rollers by directing radiation from halogen bulbs onto the surfaces of the rollers. The heat produced by halogen bulbs is, however, intense, and it has proved difficult to heat rollers consistently and reliably in this manner. It has also been found that, if the surfaces of the rollers (which are typically formed silicone) are overheated, they may become permanently damaged, which may render the entire machine inoperable.